The focus of attention can be either unitary or divided and can transition from unitary to divided while performing a task. In Experiment 1, we investigated whether alerting hastens the transition from unitary to divided attention. To this end, we employed a dual-RSVP-stream Attentional Blink task (AB; impaired perception of the second of two rapidly sequential targets) with two pairs of letter targets (T1-pair and T2-pair). One component of the AB known as Lag-1 sparing (unimpaired perception of the T2-pair when it is presented directly after the T1-pair) occurs only when the T2-pair falls in an attended location. When the T2-pair falls in an unattended location, the converse pattern occurs (Lag-1 deficit). Accordingly, we used the incidence of Lag-1 sparing/deficit to index whether a location was attended or unattended. We found that presenting a brief brightening flash of the screen (alerting) just before the T1-pair hastened the transition from the initial unitary focus to a divided focus. In Experiment 2, we pitted the hastening account against an alternative hypothesis that the flash triggers phasic activation of the Locus Coeruleus—norepinephrine neuromodulatory system, thus resetting the underlying neural networks that mediate the distribution of attention, triggering a switch from unitary to divided attention. The results of Experiment 2 were incompatible with the hastening account, but consistent with the network-reset account.

注意力的焦点可以是单一的也可以是分散的，并且可以在执行任务时从单一转移到分散。在实验 1 中，我们研究了警报是否加速了从单一注意力到分散注意力的转变。为此，我们采用了双 RSVP 流注意力眨眼任务（AB；对两个快速连续目标中的第二个目标的感知受损）和两对字母目标（T1 对和 T2 对）。AB 的一个组成部分称为 Lag-1 保留（当 T2 对直接出现在 T1 对之后时，对 T2 对的感知未受损）仅在 T2 对落在有人看管的位置时才会发生。当 T2 对落在无人看管的位置时，会出现相反的模式（Lag-1 缺陷）。因此，我们使用 Lag-1 备用/赤字的发生率来索引一个位置是有人看管还是无人看管。我们发现，在 T1 对之前出现短暂的屏幕亮光（警告）加速了从最初的单一焦点到分散焦点的转变。在实验 2 中，我们将加速解释与另一种假设相比较，即闪光触发蓝斑-去甲肾上腺素神经调节系统的阶段性激活，从而重置调节注意力分布的潜在神经网络，触发从单一注意力到分散注意力的转变。实验2的结果与加速账户不兼容，但与网络重置账户一致。我们将加速解释与另一种假设相比较，即闪光触发蓝斑-去甲肾上腺素神经调节系统的阶段性激活，从而重置调节注意力分布的潜在神经网络，触发从单一注意力到分散注意力的转变。实验2的结果与加速账户不兼容，但与网络重置账户一致。我们将加速解释与另一种假设相比较，即闪光触发蓝斑-去甲肾上腺素神经调节系统的阶段性激活，从而重置调节注意力分布的潜在神经网络，触发从单一注意力到分散注意力的转变。实验2的结果与加速账户不兼容，但与网络重置账户一致。